The objective is to further elucidate the mechanism in Escherchia coli by which one bacterial cell compartments itself into two cells. The biochemical controls of the septation process of cell division are complex, involving multiple signals and effectors, and protein-protein interactions that restructure the cell's morphology. This proposal seeks to further define these multiple factors. The specific aims of this proposal are the following: a. To isolate and clone phenotype suppressor mutations of sulB(ftsZ), ftsA,ftsQ mutants from mutated recombinant DNA gene libraries. The new mutations will be classified as gene expression-regulation mutants, interactive gene product mutants, or by-pass suppressors. b. To identify regulators involved in the synthesis of sulB(ftsZ), ftsA, ftsQ genes using gene fusions that provide a convenient way to study transcription and translation of these genes. c. To identify and characterize proteins that associate with the protein products of sulB(ftsZ), ftsA, ftsQ genes. Since the procaryotic cell division process involves a sequential series of unidirectional reactions or steps that are somehow order in time, the understanding of the septation process during cell division will aid the comprehension of development and morphological changes in other organisms. Furthermore, this knowledge of the septation process will enable us to better control bacterial growth and bacterial infections.